Electric and hybrid electric vehicles typically include high voltage battery systems connected to components that operate at high voltage. For example, a manual service disconnect (MSD) is often used to disconnect a high current power circuit and enable a technician to safely service such high voltage battery systems or associated components. The MSD is typically associated with a high voltage interlock system (HVIL) having an HVIL control circuit to monitor the mechanical continuity of the connector to a host device or battery. Known HVIL systems include electrical switch devices to open an electric circuit to thereby prevent access to electrical components until current flow is prevented or discharged. However, such electrical switch devices are often expensive and bulky. Moreover, known HVIL systems include multiple separate components that complicate assembly and subsequent maintenance of the systems. Accordingly, while such known systems do work well for their intended purpose, it is desirable to provide an improved HVIL switch device integrating multiple components into a single piece housing.